The records of 49 patients with Parkinson's disease and psychosis who
were treated with clozapine for up to 18 months were reviewed. Average
starting dose of clozapine was 16 mg. Average maximum dose was 39 mg. The
psychotic symptoms improved in 76% of the patients at 3 months, and
response to clozapine within the first year ranged from 71% to 80%. This
response allowed a maximization of levodopa dose. Improvements in scores on
the Unified Parkinson's Disease Rating Scale and tremor subscale were seen
in some patients but were not statistically significant. This study, the
largest of its kind to date, suggests that clozapine is well tolerated and
effective in treating psychosis in patients with Parkinson's disease.Abstract Teaser